A quantity of a vitamin or mineral that far exceeds the Recommended Dietary Allowance (RDA). In some cases, megadoses can be toxic and cause severe side effects.
A large quantity of medication.
In general, a megadose is a high intake of a vitamin or mineral. Some experts have defined a megadose as at least 10 times the recommended quantity. Others have suggested that a medadose exceeds the Tolerable Upper Intake Level (UL) established by the Food and Nutrition Board of the National Academy of Sciences.
Amounts of vitamins or minerals that are greatly in excess of the recommended daily allowance of vitamins, which can sometimes lead to serious health problems.
A dose of a nutrient, such as a vitamin supplement, that is 10 times greater than the recommended daily allowance for that nutrient.
An exceedingly high dosage of a vitamin, self-administered by certain individuals as a means of self-medication.